Derived from the bulb or clove of the plant. Garlic is used as a spice and to treat hyperlipidemia, hypertension, atherosclerosis, cancer, and infections. Processing can have a substantial effect on the chemical content in garlic; the volatile oil components are sensitive to heat and certain enzymes are acid-labile. Several oral garlic formulations are available, and clinical studies have addressed a variety of the proposed claims. Placebo-controlled trials on the cholesterol lowering effect of garlic yielded mixed results (16) (17) (18) (21) (22) (26). Studies evaluating the antithrombotic effects repeatedly have shown modest reduction in platelet aggregation, but varying levels of fibrinolytic activity. Research shows mixed effects with regard to reductions in blood glucose, blood pressure, or risk of cardiovascular disease (23). Frequently reported adverse events include bad breath, headache, fatigue, GI upset, diarrhea, sweating, and possible hypoglycemia (9). Because garlic is known to decrease platelet aggregation and potentially elevate the INR, it should not be used with anticoagulants or in patients with platelet dysfunction (15). Garlic appears to induce cytochrome p450 3A4 and may enhance metabolism of many medications (e.g. cyclosporin and saquinavir) (12). An analysis of several case-control studies in Europe suggests an inverse association between garlic consumption and risk of common cancers (25).